ErbB3 Governs Endothelial Dysfunction in Hypoxia-Induced Pulmonary Hypertension.

Area of Science:

• Cardiovascular Research
• Cell Biology
• Molecular Medicine

Background:

• Pulmonary hypertension (PH) involves vascular remodeling and pulmonary artery endothelial cell dysfunction.
• ErbB3 (human epidermal growth factor receptor 3) is a receptor tyrosine kinase implicated in cellular processes.
• Current PH therapies lack curative options, highlighting the need for novel therapeutic targets.

Purpose of the Study:

• To investigate the pathological role of ErbB3 in pulmonary hypertension.
• To assess ErbB3 as a potential biomarker and therapeutic target for PH.

Main Methods:

• Utilized microarray, immunofluorescence, and Western blotting to analyze ErbB3 expression.
• Employed rodent models of PH with genetic manipulation of ErbB3 (overexpression, deletion, knockdown).
• Investigated downstream mechanisms involving YB-1 and hypoxia-inducible factors in human cells.

Main Results:

• ErbB3 was significantly upregulated in PH patients' serum, lungs, and pulmonary artery endothelial cells.
• ErbB3 overexpression exacerbated PH phenotypes in mice, while ErbB3 deletion/knockdown ameliorated them.
• Identified a novel ErbB3-YB-1-HIF1α signaling pathway and an ErbB3-periostin-HIF1α positive feedback loop.
• The anti-ErbB3 antibody MM-121 demonstrated preventive and therapeutic effects in a hypoxia-induced PH model.

Conclusions:

• ErbB3 is a key mediator in the pathogenesis of pulmonary hypertension.
• ErbB3 represents a novel and promising therapeutic target for PH.
• MM-121 shows significant potential for treating PH.